A new study finds that men who drink a lot of coffee are less likely to develop potentially fatal prostate cancer. It's the latest study to show a beneficial effect from one of the world's favorite beverages.

The study included about 50,000 men who reported their coffee consumption in questionnaires every four years. Over more than two decades, the moderate coffee drinkers were somewhat less likely to develop any form of prostate cancer. But lead author Kathryn Wilson of the Harvard School of Public Health says the real difference showed up when the researchers looked at the most serious prostate cancers.

"Men who drink six or more cups of coffee per day had a 60 percent lower risk of lethal prostate cancer than men who drank no coffee," she says. "And we saw this reduction in risk for both regular and decaffeinated coffee."

Coffee is a chemically complex brew, full of antioxidants and other compounds that may affect the development of prostate cancer.

Prostate cancer is the second most common cancer among men worldwide, killing about a quarter-million people a year. Wilson says it's unclear what component or components in coffee may be reducing the prostate cancer risk - that's a target for future research.

In the meantime, she says it's too soon to say that men should drink more coffee just to reduce their risk of aggressive prostate cancer. But she says there is a growing body of scientific evidence that coffee confers a variety of real health benefits.

"It's not harmful in terms of heart disease or stroke, and it seems possibly protective for liver cancer, and it's also associated with lower risk of type 2 diabetes. So I think evidence is accumulating that coffee is at least not harmful and possibly beneficial for some health conditions. And so, you know, I think that's a source of relief to a lot of coffee drinkers."